// webgl_advanced/webgl_buffergeometry_glbufferattribute.js
import {document,window,requestAnimationFrame,cancelAnimationFrame,Event,core} from 'dhtml-weixin';
import * as THREE from '../three/Three.js';
import Stats from './jsm/libs/stats.module.js';
import { GUI } from './jsm/libs/lil-gui.module.min.js';

var requestId
Page({
	onUnload() {
		cancelAnimationFrame(requestId, this.canvas)
this.worker && this.worker.terminate()
		setTimeout(() => {
			if (this.renderer instanceof THREE.WebGLRenderer) {
				this.renderer.dispose()
				this.renderer.forceContextLoss()
				this.renderer.context = null
				this.renderer.domElement = null
				this.renderer = null
			}
		}, 0)
	},
	    webgl_touch(e) {
        const web_e = Event.fix(e)
        //window.dispatchEvent(web_e)
        //document.dispatchEvent(web_e)
        this.canvas.dispatchEvent(web_e)
    },
  async onLoad(){
const canvas3d = this.canvas =await document.createElementAsync("canvas","webgl")
var that = this
let container, stats;

let camera, scene, renderer;

let points;

const particles = 300000;
let drawCount = 10000;

init();
animate();

function init() {

    container = document.getElementById( 'container' );

    //

    renderer = that.renderer = new THREE.WebGLRenderer( { canvas:canvas3d,antialias: false } );
    renderer.setPixelRatio( window.devicePixelRatio );
    renderer.setSize( window.innerWidth, window.innerHeight );

    container.appendChild( renderer.domElement );

    //

    camera = new THREE.PerspectiveCamera( 27, window.innerWidth / window.innerHeight, 5, 3500 );
    camera.position.z = 2750;

    scene = new THREE.Scene();
    scene.background = new THREE.Color( 0x050505 );
    scene.fog = new THREE.Fog( 0x050505, 2000, 3500 );

    //

    const geometry = new THREE.BufferGeometry();

    const positions = [];
    const positions2 = [];
    const colors = [];

    const color = new THREE.Color();

    const n = 1000, n2 = n / 2; // particles spread in the cube

    for ( let i = 0; i < particles; i ++ ) {

        // positions

        const x = Math.random() * n - n2;
        const y = Math.random() * n - n2;
        const z = Math.random() * n - n2;

        positions.push( x, y, z );
        positions2.push( z * 0.3, x * 0.3, y * 0.3 );

        // colors

        const vx = ( x / n ) + 0.5;
        const vy = ( y / n ) + 0.5;
        const vz = ( z / n ) + 0.5;

        color.setRGB( vx, vy, vz );

        colors.push( color.r, color.g, color.b );

    }

    const gl = renderer.getContext();

    const pos = gl.createBuffer();
    gl.bindBuffer( gl.ARRAY_BUFFER, pos );
    gl.bufferData( gl.ARRAY_BUFFER, new Float32Array( positions ), gl.STATIC_DRAW );

    const pos2 = gl.createBuffer();
    gl.bindBuffer( gl.ARRAY_BUFFER, pos2 );
    gl.bufferData( gl.ARRAY_BUFFER, new Float32Array( positions2 ), gl.STATIC_DRAW );

    const rgb = gl.createBuffer();
    gl.bindBuffer( gl.ARRAY_BUFFER, rgb );
    gl.bufferData( gl.ARRAY_BUFFER, new Float32Array( colors ), gl.STATIC_DRAW );

    const posAttr1 = new THREE.GLBufferAttribute( pos, gl.FLOAT, 3, 4, particles );
    const posAttr2 = new THREE.GLBufferAttribute( pos2, gl.FLOAT, 3, 4, particles );
    geometry.setAttribute( 'position', posAttr1 );

    setInterval( function () {

        const attr = geometry.getAttribute( 'position' );

        geometry.setAttribute( 'position', ( attr === posAttr1 ) ? posAttr2 : posAttr1 );

    }, 2000 );

    geometry.setAttribute( 'color', new THREE.GLBufferAttribute( rgb, gl.FLOAT, 3, 4, particles ) );

    //

    const material = new THREE.PointsMaterial( { size: 15, vertexColors: true } );

    points = new THREE.Points( geometry, material );

    // Choose one:
    // geometry.boundingSphere = ( new THREE.Sphere() ).set( new THREE.Vector3(), Infinity );
    points.frustumCulled = false;

    scene.add( points );

    //

    stats = new Stats();
    container.appendChild( stats.dom );

    //

    window.addEventListener( 'resize', onWindowResize );

}

function onWindowResize() {

    camera.aspect = window.innerWidth / window.innerHeight;
    camera.updateProjectionMatrix();

    renderer.setSize( window.innerWidth, window.innerHeight );

}

//

function animate() {

    requestId = requestAnimationFrame(animate);

    render();
    stats.update();

}

function render() {

    drawCount = ( Math.max( 5000, drawCount ) + Math.floor( 500 * Math.random() ) ) % particles;
    points.geometry.setDrawRange( 0, drawCount );

    const time = Date.now() * 0.001;

    points.rotation.x = time * 0.1;
    points.rotation.y = time * 0.2;

    renderer.render( scene, camera );

}

}
})